Industrial and commercial burners are used across a broad range of applications, including process heat sources, flame treatment systems, steam boilers for electrical power generation, and hot gas sources for gas turbines. Collectively, industrial and commercial burners are a significant source of air pollution. Notwithstanding pollutants released by fuel, flames produced by even “clean-burning” fuels such as hydrogen, hydrocarbon gases, and pure hydrocarbon liquids produce pollutants such as oxides of nitrogen (collectively referred to as “NOx” herein). Hydrocarbon fuels can further release carbon monoxide (CO), and fuel slip into the atmosphere.
In a conventional combustion system typical of industrial and commercial burners, the combustion reaction is relatively uncontrolled. That is, a flame can vary in conformation such that its shape and location at any particular point in time is unpredictable. This unpredictability, combined with high peak temperatures encountered especially at the stoichiometric interface (the visible surface) in a diffusion flame can cause operational problems such as coking of reaction tubes and/or uneven heating of steam tubes. Moreover, the length of a conventional flame causes a relatively long residence time during which combustion air (including molecular nitrogen) is subject to high temperature.
What is needed is a technology for reducing pollutants released by combustion systems such as industrial and commercial burners. What is also needed is a technology that can improve flame control in such systems.